The present invention relates to optical means, schemes and arrangements and, more particularly, to optical means, schemes and arrangements for decorative applications. More specifically, although of course not solely limiting, this invention relates to optical means, schemes and arrangements for decorative applications utilizing elongated optical guides, such as optical fibers. This invention also relates to articles, devices and arrangements incorporating the optical means, schemes and arrangements forming the subject of this present invention.
Optical means, schemes and arrangements (collectively xe2x80x9coptical meansxe2x80x9d) find wide applications in everyday life. For example, outdoor commercial signboards have been constructed with optical fibers to provide variable colour illuminated displays to attract customers and the external walls of high-rise buildings have been decorated with optical fibers colour changing effects to attract the attention of the public. On items of a smaller scale, optical means have also been utilized in domestic appliances such as refrigerators as well as decorative articles, such as Christmas trees and other seasonal decorations. To enhance the aesthetic appeal of such appliances and decorative articles, the optical means are usually provided with variable colour or colour changing effects.
For example, optical fibers are used in artificial Christmas trees to produce distributed variable colour effects around the Christmas trees. This is done by utilizing a variable optical means comprising a transparent colour disk illuminated by a filament lamp and driven into rotation by an electric motor to produce a colour changing effect at the downstream ends of the optical fibers. However, this type of conventional variable colour optical means is bulky because of the large volume required to accommodate the motor and the rotating colour disk. Furthermore, such an optical means is also energy consuming which is not suitable for use with a portable device or with a stored energy source. In addition, the waste heat generated by the filament lamp creates problems for heat dissipation as well as posing potential fire hazards.
Hence, it will be beneficial if there can be provided improved optical means which alleviate at least some of the shortcomings associated with conventional optical means. Furthermore, in devising such improved optical means, it will be desirable if movable parts are minimized or even eliminated to prolong operating life and reduce the need of regular maintenance.
Accordingly, it is an object of the present invention to provide optical means, schemes and arrangements for generating a multi-colour or a changing colour display which alleviate shortcomings of existing optical means. More particularly, it is an object of the present invention to provide optical means, schemes and arrangements which provide colour mixing or variable colour output with minimal movable parts. Preferably, such optical means does not require an incandescent light source which is highly energy consuming as well as generating excessive heat.
It is a further object of the present invention to provide a compact optical means with a non-incandescent light source for decorative applications utilizing optical fibers for dispersing coloured light generated by the optical means.
Broadly speaking, it is a general object of the present invention to provide a compact, reliable and efficient optical means suitable for use in optical fiber based decorative applications. At a minimum, it is an object of the present invention to provide an useful optical means for the choice of the public.
According to a first aspect of the present invention, there is provided optical means including an optical source, selection means and optical guiding means, said optical source includes means for producing a plurality of optical regions of different colours, said optical guiding means include a plurality of elongated optical guides for guiding light coupled to the upstream ends of said optical guides to their downstream ends, said selection means includes means for selectively aligning the upstream ends of said optical guides to one or a plurality of said optical regions.
Preferably, said optical source includes at least a first and a second light emitting sources, said first and said second light emitting sources being disposed to form a first optical region, a second optical region and a combination optical region, said first and said second optical regions being formed by projection of light originating respectively from said first light emitting source and said light emitting source, said combination optical region being formed by co-operative projection of light originating from both said first light emitting source and said second light emitting source.
Preferably, said first and said second light emitting sources include light emitting diodes (LEDs) respectively of a first colour and a second colour which are not the same, said first and said second optical regions being generally covered with light of said first and said second colour, said combination optical region being a region covered with light resulting from mixing of light from said first and second light emitting sources.
Preferably, the intensity of light of each of said first and second light emitting diodes are variable.
Preferably, the axes of said first and second LEDs are generally parallel, said first, second and combination optical regions being formed by projection of light emitted from said LEDs, the cumulative area of said optical regions increases with the distance along the direction of light emission from said LEDs.
Preferably, said first and second LEDs are connected to a intensity controlling means for varying the light intensity of said LEDs.
Preferably, the colour of said combination optical region is variable by varying the relative intensity of said first and said second LEDs.
Preferably, each of said first and second LEDs has a viewing angle exceeding 9xc2x0.
Preferably, the separation (D) between said first and second LEDs does not exceed 12 mm.
Preferably, the separation between said combination optical region and the light emitting plane of the said LEDs is between D/3 and 3D.
Preferably, said optical guides are PVC optical fibers with a perimeter not exceeding 1.5 xcfx80mm.
Preferably, said optical source includes at least an LED and a colour filter.
Preferably, said selection means includes partitioning means defining regions corresponding to at least one of said optical regions.
Preferably, said optical means preferably includes a third light emitting source, said third light emitting source being capable of producing light of a colour different from said first and said second light emitting sources, said third light source emits light to form a third optical region and co-operates with said first and said second light emitting sources to form a tertiary optical region, said selection means includes means to couple the upstream ends of said optical guides to optical regions including said tertiary optical region.
According to a second aspect of the present invention, there is provided articles, for example consumer articles, apparel articles, shoes or decorative articles including the invention of optical means characterized or described under this section or throughout the specification.